Merge "Use an EventBus to manage star icons"

gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeCache.java

@@ -38,7 +38,6 @@ public class ChangeCache {
   private Change.Id changeId;
   private ChangeDetailCache detail;
   private ListenableValue<ChangeInfo> info;
-  private StarCache starred;
 
   protected ChangeCache(Change.Id chg) {
     changeId = chg;
@@ -61,11 +60,4 @@ public class ChangeCache {
     }
     return info;
   }
-
-  public StarCache getStarCache() {
-    if (starred == null) {
-      starred = new StarCache(changeId);
-    }
-    return starred;
-  }
 }

gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeDetailCache.java

@@ -65,6 +65,7 @@ public class ChangeDetailCache extends ListenableValue<ChangeDetail> {
   public static void setChangeDetail(ChangeDetail detail) {
     Change.Id chgId = detail.getChange().getId();
     ChangeCache.get(chgId).getChangeDetailCache().set(detail);
+    StarredChanges.fireChangeStarEvent(chgId, detail.isStarred());
   }
 
   private final Change.Id changeId;

gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeScreen.java

@@ -28,9 +28,9 @@ import com.google.gerrit.common.data.ChangeDetail;
 import com.google.gerrit.common.data.ChangeInfo;
 import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.Change;
+import com.google.gerrit.reviewdb.client.Change.Status;
 import com.google.gerrit.reviewdb.client.ChangeMessage;
 import com.google.gerrit.reviewdb.client.PatchSet;
-import com.google.gerrit.reviewdb.client.Change.Status;
 import com.google.gwt.event.dom.client.ChangeEvent;
 import com.google.gwt.event.dom.client.ChangeHandler;
 import com.google.gwt.event.dom.client.KeyPressEvent;
@@ -42,7 +42,6 @@ import com.google.gwt.user.client.ui.DisclosurePanel;
 import com.google.gwt.user.client.ui.FlowPanel;
 import com.google.gwt.user.client.ui.Grid;
 import com.google.gwt.user.client.ui.HorizontalPanel;
-import com.google.gwt.user.client.ui.Image;
 import com.google.gwt.user.client.ui.InlineLabel;
 import com.google.gwt.user.client.ui.Label;
 import com.google.gwt.user.client.ui.ListBox;
@@ -60,9 +59,7 @@ public class ChangeScreen extends Screen
   private final Change.Id changeId;
   private final PatchSet.Id openPatchSetId;
   private ChangeDetailCache detailCache;
-  private StarCache starred;
 
-  private Image starChange;
   private ChangeDescriptionBlock descriptionBlock;
   private ApprovalTable approvals;
 
@@ -155,8 +152,6 @@ public class ChangeScreen extends Screen
     detailCache = cache.getChangeDetailCache();
     detailCache.addValueChangeHandler(this);
 
-    starred = cache.getStarCache();
-
     addStyleName(Gerrit.RESOURCES.css().changeScreen());
 
     keysNavigation = new KeyCommandSet(Gerrit.C.sectionNavigation());
@@ -165,13 +160,13 @@ public class ChangeScreen extends Screen
     keysNavigation.add(new ExpandCollapseDependencySectionKeyCommand(0, 'd', Util.C.expandCollapseDependencies()));
 
     if (Gerrit.isSignedIn()) {
-      keysAction.add(starred.new KeyCommand(0, 's', Util.C.changeTableStar()));
+      StarredChanges.Icon star = StarredChanges.createIcon(changeId, false);
+      star.setStyleName(Gerrit.RESOURCES.css().changeScreenStarIcon());
+      setTitleWest(star);
+
+      keysAction.add(StarredChanges.newKeyCommand(star));
       keysAction.add(new PublishCommentsKeyCommand(0, 'r', Util.C
           .keyPublishComments()));
-
-      starChange = starred.createStar();
-      starChange.setStyleName(Gerrit.RESOURCES.css().changeScreenStarIcon());
-      setTitleWest(starChange);
     }
 
     descriptionBlock = new ChangeDescriptionBlock();

gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeTable.java

@@ -145,7 +145,7 @@ public class ChangeTable extends NavigationTable<ChangeInfo> {
   protected void onStarClick(final int row) {
     final ChangeInfo c = getRowItem(row);
     if (c != null && Gerrit.isSignedIn()) {
-       ChangeCache.get(c.getId()).getStarCache().toggleStar();
+      ((StarredChanges.Icon) table.getWidget(row, C_STAR)).toggleStar();
     }
   }
 
@@ -198,7 +198,7 @@ public class ChangeTable extends NavigationTable<ChangeInfo> {
     final String idstr = c.getKey().abbreviate();
     table.setWidget(row, C_ARROW, null);
     if (Gerrit.isSignedIn()) {
-      table.setWidget(row, C_STAR, cache.getStarCache().createStar());
+      table.setWidget(row, C_STAR, StarredChanges.createIcon(c.getId(), c.isStarred()));
     }
     table.setWidget(row, C_ID, new TableChangeLink(idstr, c));
 

gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/StarCache.java

@@ -1,139 +0,0 @@
-// Copyright (C) 2012 The Android Open Source Project
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package com.google.gerrit.client.changes;
-
-import com.google.gerrit.client.Gerrit;
-import com.google.gerrit.client.rpc.GerritCallback;
-import com.google.gerrit.client.ui.NeedsSignInKeyCommand;
-import com.google.gerrit.common.data.ChangeDetail;
-import com.google.gerrit.common.data.ChangeInfo;
-import com.google.gerrit.common.data.ToggleStarRequest;
-import com.google.gerrit.reviewdb.client.Change;
-
-import com.google.gwt.event.dom.client.ClickEvent;
-import com.google.gwt.event.dom.client.ClickHandler;
-import com.google.gwt.event.dom.client.KeyPressEvent;
-import com.google.gwt.event.logical.shared.HasValueChangeHandlers;
-import com.google.gwt.event.logical.shared.ValueChangeEvent;
-import com.google.gwt.event.logical.shared.ValueChangeHandler;
-import com.google.gwt.event.shared.GwtEvent;
-import com.google.gwt.event.shared.HandlerManager;
-import com.google.gwt.event.shared.HandlerRegistration;
-import com.google.gwt.resources.client.ImageResource;
-import com.google.gwt.user.client.ui.Image;
-import com.google.gwtjsonrpc.common.VoidResult;
-
-public class StarCache implements HasValueChangeHandlers<Boolean> {
-  public class KeyCommand extends NeedsSignInKeyCommand {
-    public KeyCommand(int mask, char key, String help) {
-      super(mask, key, help);
-    }
-
-    @Override
-    public void onKeyPress(final KeyPressEvent event) {
-      StarCache.this.toggleStar();
-    }
-  }
-
-  ChangeCache cache;
-
-  private HandlerManager manager = new HandlerManager(this);
-
-  public StarCache(final Change.Id chg) {
-    cache = ChangeCache.get(chg);
-  }
-
-  public boolean get() {
-    ChangeDetail detail = cache.getChangeDetailCache().get();
-    if (detail != null) {
-      return detail.isStarred();
-    }
-    ChangeInfo info = cache.getChangeInfoCache().get();
-    if (info != null) {
-      return info.isStarred();
-    }
-    return false;
-  }
-
-  public void set(final boolean s) {
-    if (Gerrit.isSignedIn() && s != get()) {
-      final ToggleStarRequest req = new ToggleStarRequest();
-      req.toggle(cache.getChangeId(), s);
-
-      Util.LIST_SVC.toggleStars(req, new GerritCallback<VoidResult>() {
-        public void onSuccess(final VoidResult result) {
-          setStarred(s);
-          fireEvent(new ValueChangeEvent<Boolean>(s){});
-        }
-      });
-    }
-  }
-
-  private void setStarred(final boolean s) {
-    ChangeDetail detail = cache.getChangeDetailCache().get();
-    if (detail != null) {
-      detail.setStarred(s);
-    }
-    ChangeInfo info = cache.getChangeInfoCache().get();
-    if (info != null) {
-      info.setStarred(s);
-    }
-  }
-
-  public void toggleStar() {
-    set(!get());
-  }
-
-  @SuppressWarnings("unchecked")
-  public Image createStar() {
-    final Image star = new Image(getResource());
-    star.setVisible(Gerrit.isSignedIn());
-
-    star.addClickHandler(new ClickHandler() {
-      @Override
-      public void onClick(final ClickEvent event) {
-        StarCache.this.toggleStar();
-      }
-    });
-
-    @SuppressWarnings("rawtypes")
-    ValueChangeHandler starUpdater = new ValueChangeHandler() {
-        @Override
-        public void onValueChange(ValueChangeEvent event) {
-          star.setResource(StarCache.this.getResource());
-        }
-      };
-
-    cache.getChangeDetailCache().addValueChangeHandler(starUpdater);
-    cache.getChangeInfoCache().addValueChangeHandler(starUpdater);
-
-    this.addValueChangeHandler(starUpdater);
-
-    return star;
-  }
-
-  private ImageResource getResource() {
-    return get() ? Gerrit.RESOURCES.starFilled() : Gerrit.RESOURCES.starOpen();
-  }
-
-  public void fireEvent(GwtEvent<?> event) {
-    manager.fireEvent(event);
-  }
-
-  public HandlerRegistration addValueChangeHandler(
-      ValueChangeHandler<Boolean> handler) {
-    return manager.addHandler(ValueChangeEvent.getType(), handler);
-  }
-}

gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/StarredChanges.java

@@ -0,0 +1,216 @@
+// Copyright (C) 2012 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.client.changes;
+
+import com.google.gerrit.client.Gerrit;
+import com.google.gerrit.client.rpc.GerritCallback;
+import com.google.gerrit.common.data.ToggleStarRequest;
+import com.google.gerrit.reviewdb.client.Change;
+import com.google.gwt.event.dom.client.ClickEvent;
+import com.google.gwt.event.dom.client.ClickHandler;
+import com.google.gwt.event.dom.client.KeyPressEvent;
+import com.google.gwt.event.shared.EventBus;
+import com.google.gwt.event.shared.SimpleEventBus;
+import com.google.gwt.resources.client.ImageResource;
+import com.google.gwt.user.client.ui.Image;
+import com.google.gwtexpui.globalkey.client.KeyCommand;
+import com.google.gwtjsonrpc.common.VoidResult;
+import com.google.web.bindery.event.shared.Event;
+import com.google.web.bindery.event.shared.HandlerRegistration;
+
+/** Supports the star icon displayed on changes and tracking the status. */
+public class StarredChanges {
+  private static final EventBus eventBus = new SimpleEventBus();
+  private static final Event.Type<ChangeStarHandler> TYPE =
+      new Event.Type<ChangeStarHandler>();
+
+  /** Handler that can receive notifications of a change's starred status. */
+  public static interface ChangeStarHandler {
+    public void onChangeStar(ChangeStarEvent event);
+  }
+
+  /** Event fired when a star changes status. The new status is reported. */
+  public static class ChangeStarEvent extends Event<ChangeStarHandler> {
+    private boolean starred;
+
+    public ChangeStarEvent(Change.Id source, boolean starred) {
+      setSource(source);
+      this.starred = starred;
+    }
+
+    public boolean isStarred() {
+      return starred;
+    }
+
+    @Override
+    public Type<ChangeStarHandler> getAssociatedType() {
+      return TYPE;
+    }
+
+    @Override
+    protected void dispatch(ChangeStarHandler handler) {
+      handler.onChangeStar(this);
+    }
+  }
+
+  /**
+   * Create a star icon for the given change, and current status. Returns null
+   * if the user is not signed in and cannot support starred changes.
+   */
+  public static Icon createIcon(Change.Id source, boolean starred) {
+    return Gerrit.isSignedIn() ? new Icon(source, starred) : null;
+  }
+
+  /** Make a key command that toggles the star for a change. */
+  public static KeyCommand newKeyCommand(final Icon icon) {
+    return new KeyCommand(0, 's', Util.C.changeTableStar()) {
+      @Override
+      public void onKeyPress(KeyPressEvent event) {
+        icon.toggleStar();
+      }
+    };
+  }
+
+  /** Add a handler to listen for starred status to change. */
+  public static HandlerRegistration addHandler(
+      Change.Id source,
+      ChangeStarHandler handler) {
+    return eventBus.addHandlerToSource(TYPE, source, handler);
+  }
+
+  /**
+   * Broadcast the current starred value of a change to UI widgets. This does
+   * not RPC to the server and does not alter the starred status of a change.
+   */
+  public static void fireChangeStarEvent(Change.Id id, boolean starred) {
+    eventBus.fireEventFromSource(
+        new ChangeStarEvent(id, starred),
+        id);
+  }
+
+  /**
+   * Set the starred status of a change. This method broadcasts to all
+   * interested UI widgets and sends an RPC to the server to record the
+   * updated status.
+   */
+  public static void toggleStar(
+      final Change.Id changeId,
+      final boolean newValue) {
+    if (next == null) {
+      next = new ToggleStarRequest();
+    }
+    next.toggle(changeId, newValue);
+    fireChangeStarEvent(changeId, newValue);
+    if (!busy) {
+      start();
+    }
+  }
+
+  private static ToggleStarRequest next;
+  private static boolean busy;
+
+  private static void start() {
+    final ToggleStarRequest req = next;
+    next = null;
+    busy = true;
+
+    Util.LIST_SVC.toggleStars(req, new GerritCallback<VoidResult>() {
+      @Override
+      public void onSuccess(VoidResult result) {
+        if (next != null) {
+          start();
+        } else {
+          busy = false;
+        }
+      }
+
+      @Override
+      public void onFailure(Throwable caught) {
+        rollback(req);
+        if (next != null) {
+          rollback(next);
+          next = null;
+        }
+        busy = false;
+        super.onFailure(caught);
+      }
+    });
+  }
+
+  private static void rollback(ToggleStarRequest req) {
+    if (req.getAddSet() != null) {
+      for (Change.Id id : req.getAddSet()) {
+        fireChangeStarEvent(id, false);
+      }
+    }
+    if (req.getRemoveSet() != null) {
+      for (Change.Id id : req.getRemoveSet()) {
+        fireChangeStarEvent(id, true);
+      }
+    }
+  }
+
+  public static class Icon extends Image
+      implements ChangeStarHandler, ClickHandler {
+    private final Change.Id changeId;
+    private boolean starred;
+    private HandlerRegistration handler;
+
+    Icon(Change.Id changeId, boolean starred) {
+      super(resource(starred));
+      this.changeId = changeId;
+      this.starred = starred;
+      addClickHandler(this);
+    }
+
+    /**
+     * Toggles the state of the star, as if the user clicked on the image. This
+     * will broadcast the new star status to all interested UI widgets, and RPC
+     * to the server to store the changed value.
+     */
+    public void toggleStar() {
+      StarredChanges.toggleStar(changeId, !starred);
+    }
+
+    @Override
+    protected void onLoad() {
+      handler = StarredChanges.addHandler(changeId, this);
+    }
+
+    @Override
+    protected void onUnload() {
+      handler.removeHandler();
+      handler = null;
+    }
+
+    @Override
+    public void onChangeStar(ChangeStarEvent event) {
+      setResource(resource(event.isStarred()));
+      starred = event.isStarred();
+    }
+
+    @Override
+    public void onClick(ClickEvent event) {
+      toggleStar();
+    }
+
+    private static ImageResource resource(boolean starred) {
+      return starred ? Gerrit.RESOURCES.starFilled() : Gerrit.RESOURCES.starOpen();
+    }
+  }
+
+  private StarredChanges() {
+  }
+}